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Integrated crop–livestock (ICL) systems have shown potential to provide a variety of environmental benefits including soil carbon (C) increases relative to conventional row cropping systems. However, studies documenting C dynamics of ICL systems in the northern Great Plains are lacking relative to other agroecosystems. Soil carbon dioxide (CO2) efflux, crop biomass, and soil organic matter (SOM) pools were monitored over 3 years in an ICL rotation (corn [Zea mays L.]/soybean [Glycine max L.]–spring wheat [Triticum aestivum L.] + cover crop–cover crop) with fall grazing, a conventional cropping system rotation (corn–spring wheat–soybean) and fall grazed and ungrazed mixed‐grass pasture near Mandan, ND. Cropped treatments were under no‐till management. Annual aboveground crop residue biomass C was similar in the ICL and conventional systems, while less in the grazed pasture (4.18, 3.83, and 1.21 Mg C ha−1 year−1 respectively; p = 0.039). Annual soil CO2 efflux was greater in the ICL, grazed, and ungrazed pasture systems than the conventional system (8.05, 8.73, 8.25, and 5.81 Mg C ha−1 year−1, respectively; p < 0.001). Among crop phases in the ICL and conventional cropping systems, cover crops contributed to greater CO2 efflux in the spring and fall. SOM and C mineralization were greater at 0–5 cm in the ICL system compared to the conventional cropping system (6.6% vs. 6.3%, p = 0.028 and 248 vs. 184 mg CO2–C kg−1, p < 0.001, respectively). Interseeded cover crops in ICL systems can contribute increased root respiration and enhanced SOM pools relative to conventional cropping systems under semiarid conditions. Core Ideas: Soil carbon (C) dynamics in integrated crop–livestock (ICL) systems are not well understood.Soil carbon dioxide (CO2) efflux and labile pools of soil organic matter (SOM) were evaluated over 3 years.Soil CO2 efflux was greater in the ICL system compared to conventional cropping.SOM and C mineralization were also greater in the ICL system compared to conventional cropping.Interseeded cover crops in ICL systems can enhance soil C pools and biological activity. [ABSTRACT FROM AUTHOR]

There are concerns that restored grasslands currently under the Conservation Reserve Program (CRP) will experience increased soil erosion when they are returned to crop production. Our objective was to compare runoff, erosion, and erodibility on CRP land converted to annual hay production (permanent hayed, PH) and crop production under conventional-till (preplant disk tillage, CT) and no-till (NT) management. Erosion study was conducted in central North Dakota on Typic Argiustoll soil 6 yr after the CRP land had been converted to hay production and crop production with a spring wheat (Triticum aestivum L.)--winter wheat-dry pea (Pisum sativum L.) rotation. Runoff volumes and soil loss (by alum precipitation of sediment) were measured on 1.5 by 5 m bordered plots on 4% slope under a rainfall simulator delivering 1-to 3-h rains at 50 or 75 mm [h.sup.-1], followed by three rains of 20 min or less at rates from 25 to 125 mm [h.sup.-1.] Erodibility was calculated from ratios and regressions of soil loss rates versus runoff rates measured at relative steady state. Runoff rates from 50 and 75 mm [h.sup.-1] rains for CT, NT, and PH averaged 9, 12, and 21 mm [h.sup.-1], respectively, and supported soil loss rates of 20, 7, and 8 g [m.sup.-2] [h.sup.-1]. Erodibility of undisturbed CT, NT, and PH was 1.65, 0.29, and 0.28 g [m.sup.-2] [mm.sup.-1], respectively, showing NT did not differ from PH and that CT management increased erodibility six-fold above PH. Thorough disk tillage increased erodibility three-fold over CT, 15-fold over NT, and nine-fold over PH. Complete, nondisturbing residue removal increased erodibility less than tillage, from 1.2 times for CT to 2.5 times for NT. Chemically weeded NT exhibited the same low erodibility as the grassland PH treatment under the conditions of study--4% land slope, above average precipitation, and a residue-productive crop rotation. However, erodibility of tilled NT was significantly higher than that of tilled PH, showing the higher inherent stability of grassland surface soil with its perennial plant rant structures.

There are concerns that restored grasslands currently under the Conservation Reserve Program (CRP) will experience increased soil erosion when they are returned to crop production. Our objective was to compare runoff, erosion, and erodibility on CRP land converted to annum hay production (permanent hayed, PH) and crop production under conventional-till (preplant disk tillage, CT) and no-till (NT) management. Erosion study was conducted in central North Dakota on Typic Argiustoll soil 6 yr after the CRP land had been converted to hay production and crop production with a spring wheat (Triticum aestivura L.) -winter wheat-dry pea (Pisum sativum L.) rotation. Runoff volumes and soil loss (by alum precipitation of sediment) were measured on 1.5 by 5 m bordered plots on 4% slope under a rainfall simulator delivering 1- to 3-h rains at 50 or 75 mm h-1, followed by three rains of 20 min or less at rates from 25 to 125 mm h-1. Erodibility was calculated from ratios and regressions of soil loss rates versus runoff rates measured at relative steady state. Runoff rates from 50 and 75 mm h-1 rains for CT, NT, and PH averaged 9, 12, and 21 mm h-1, respectively, and supported soil loss rates of 20, 7, and 8 g m-2 h-1. Erodibility of undisturbed CT, NT, and PH was 1.65, 0.29, and 0.28 g m-2 mm-1, respectively, showing NT did not differ from PH and that CT management increased erodibility six-fold above PH. Thorough disk tillage increased erodibility three-fold over CT, 15-fold over NT, and nine-fold over PH. Complete, nondisturbing residue removal increased erodibility less than tillage, from 1.2 times for CT to 2.5 times for NT. Chemically weeded NT exhibited the same Iow erodibility as the grassland PH treatment under the conditions of study-4% land slope, above average precipitation, and a residueproductive crop rotation. However, erodibility of tilled NT was significantiy higher than that of tilled PH, showing the higher inherent stability of grassland surface soil with its perennial plant root structures. [ABSTRACT FROM AUTHOR]